Project Summary/Abstract Elevated intracellular free Zn2+ concentrations ([Zn2+]i) have been implicated in the neuronal death caused by stroke. Therefore, a therapy that restores low [Zn2+]i has the potential to improve the outcome of stroke. The goal of proposed research is to design such a therapy. Preliminary studies on hippocampal neurons indicate that an intracellular acidification similar to that taking place during stroke causes [Zn2+]i elevations due to Zn2+ release from intracellular stores. We will determine the role of low affinity Zn2+ ligands, such as adenine nucleotides, in these [Zn2+]i elevations and establish whether neuronal viability can be improved by a specific chelation of acid-induced [Zn2+]i elevations. In particular, we will design a method of Zn2+ chelation that specifically targets these acid-induced [Zn2+]i elevations. The research will be conducted on primary hippocampal neurons from mice. Aim 1 will clarify which low affinity intracellular Zn2+ ligands release this ion when the pH drops into a stroke-characteristic range. In Aim 2, a method will be developed to specifically chelate acid-induced [Zn2+]i elevations. Aim 3 will determine whether this method of Zn2+ chelation improves the viability of neurons exposed to oxygen and glucose-deprivation. If it does, our method will provide a framework for the development of therapy that counteracts excessive [Zn2+]i elevations during stroke.